sched/cache: Record per LLC utilization to guide cache aware scheduling decisions

When a system becomes busy and a process's preferred LLC is
saturated with too many threads, tasks within that LLC migrate
frequently. These in LLC migrations introduce latency and degrade
performance. To avoid this, task aggregation should be suppressed
when the preferred LLC is overloaded, which requires a metric to
indicate LLC utilization.

Record per LLC utilization/cpu capacity during periodic load
balancing. These statistics will be used in later patches to decide
whether tasks should be aggregated into their preferred LLC.

Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/a48151b3d57f2a42a5971aaead1b7f81e69229f4.1775065312.git.tim.c.chen@linux.intel.com
This commit is contained in:
Chen Yu 2026-04-01 14:52:15 -07:00 • committed by Peter Zijlstra
commit f025ef2753
2 changed files with 74 additions and 0 deletions